#include <iostream> 
#include <cstdlib>
#include <cmath>  //<math.h>

using namespace std;

int main(int argc, char *argv[])
{  system("chcp 1253");

  int a,b;
  char ch;

  printf("Do you want to:\n");
  printf("Add, Subtract, Multipy, or Divide\n");
  /* force user to enter valid response */
  do {
       cout<<"Enter operation's first letter:  ";
       cin>>ch;  cout<<"\n";
      } while (ch!='A' && ch!='S' && ch!='M' && ch!='D');
  cout<<"Enter first number: ";
  cin>>a;
  cout<<"Enter second number:  ";
  cin>>b;

  switch (ch) {
     case 'A'  : cout<<a+b;
                 break;
     case 'S'  : cout<<a-b;
                 break;
     case 'M'  : cout<<a*b;
                 break;
     case 'D'  : if (b!=0) cout<<a/b;
                 break;
  }
  cout<<endl;
         
   system("PAUSE");
   return 0;
}